IB DP Chemistry: SL复习笔记4.1.1 Forming Ions

• As a general rule, metals are on the left of the Periodic Table and non-metals are on the right-hand side
• Ionic bonds involve the transfer of electrons from a metallic element to a non-metallic element
• Transferring electrons usually leaves the metal and the non-metal with a full outer shell
• Metals lose electrons from their valence shell forming positively charged cations
• Non-metal atoms gain electrons forming negatively charged anions
• Once the atoms become ions, their electronic configurations are the same as a noble gas.
  • A sodium ion (Na⁺) has the same electronic configuration as neon: [2,8]
  • A chloride ion (Cl^-) also has the same electronic configuration as argon: [2,8,8]

Forming cations by the removal of electrons from metals

Forming anions by the addition of electrons to nonmetals

• Cations and anions are oppositely charged and therefore attracted to each other
• Electrostatic attractions are formed between the oppositely charged ions to form ionic compounds
• This form of attraction is very strong and requires a lot of energy to overcome
  • This causes high melting points in ionic compounds

Cations and anions bond together using strong electrostatic forces, which require a lot of energy to overcome